Yahoo Complaint Feedback Loop service FAQ

Yahoo provides the Complaint Feedback Loop (CFL) service to bulk mail senders and mail list providers to improve the accuracy of their mail lists. By keeping bulk senders informed about how their email is being received by our users, it improves the flow of email for both senders and recipients reducing the amount of unsolicited email our users receive.

Yahoo provides the Complaint Feedback Loop (CFL) service to bulk mail senders and mail list providers to improve the accuracy of their mail lists. By keeping bulk senders informed about how their email is being received by our users, it improves the flow of email for both senders and recipients reducing the amount of unsolicited email our users receive.

Frequently asked questions

When a user clicks the “report spam” button, the message is processed by Yahoo SpamGuard. If the original sender has submitted their domain to the CFL program, Yahoo sends them a copy so they can improve their campaign by removing Yahoo accounts that consider the message to be spam.

It’s recommended that you use a dedicated email address for this purpose.

Yahoo uses the domain in your DomainKeys or DKIM signature to determine the original sender because it survives forwarding. This ensures that we can route the report to the correct sender, even if the message was forwarded through another IP address.

If the message isn't signed or the DomainKey or DKIM signature can’t be verified it won’t be included in the CFL.

For bulk commercial senders or senders of transactional mail, DomainKeys or DKIM is the best option.

A report is generated in the Abuse Feedback Reporting Format (ARF) every time a Yahoo user marks a message as “spam.” The report includes the message (with full headers, nothing “munged” or redacted), and some additional metadata.

The From: header reads: ‘Yahoo Mail AntiSpam Feedback '.

The SMTP MAIL FROM (envelope sender) is formatted as: ‘cfl.-=@returns.bulk.yahoo.com’.

The source IP address varies, but every report is signed with DomainKeys or DKIM using the signing domain ‘arf.mail.yahoo.com’. That signing domain is only used for that purpose.

Yahoo doesn’t provide sample reports customized for your domain, but there’s an example in the ARF specification linked to above.

You only need to submit the domains you use to send DomainKeys or DKIM signed messages to Yahoo accounts. For example, If you own both example.com and example.net, but only sign with example.com, you don't need to set up a complaint feedback loop for example.net.

Messages automatically filtered to the Bulk or Spam folder can’t be reported as spam.

When a message is filtered by Yahoo SpamGuard, the recipient would need to check their spam folder to see the email. Automatically filtered messages have met certain criteria to be considered spam by our algorithms.

Yahoo is streamlining customer care and CFL requests by taking over the hosted CFL sign-up page from Return Path. Yahoo and Return Path continue work on other projects such as the Certification program, DMARC and Email Fraud Protection.